This research proposal will utilize the developmental system leading to dormant spore formation in Bacillus subtilis in an investigation of the genetic control of cellular differentiation. It is proposed to define, isolate, and characterize sporulation genes by DNA cloning procedures and electron microscopy. Portions of the early sporulation genes will undergo DNA sequence analysis to determine nucleotide signals which may regulate their activity. In addition, it is proposed to construct gene cloning vectors from B. subtilis bacteriophages for the isolation and analysis of proteins specified by sporulation genes. The ultimate objective of these studies is to gain a better understanding of the nature of the genetic control of biochemical functions during cellular differentiation.